In this Phase II Small Business Innovation Research (SBIR) project, Luna Innovations and its partners Lawrence Livermore National Laboratory (LLNL), Nooter/Eriksen, and the University of Illinois at Chicago will address the materials optimization, design, and scale up of solid phase supports that have the potential to sustainably operate in dual phase membranes at high carbon dioxide (CO₂) separation rates and thermally favorable conditions. Dual phase membranes consist of a porous solid material supporting a non-volatile liquid electrolyte and enable passive CO₂ separation from flue gas, allowing for lower energy costs at large scale. Research studies by LLNL have led to using yttria-stabilized zirconia (YSZ) – an inert, high-strength ceramic – as a highly promising support material in dual phase membranes for both pre-combustion and post-combustion CO₂ capture. Luna’s complimentary U.S. Department of Energy (DOE) SBIR program (DE-SC0015123) is focused on optimizing the liquid phase portion of the technology for post-combustion CO₂ capture, while the feasibility, stability, and scalability of the solid phase support under relevant operational conditions have yet to be explored and will be the focus of this project. YSZ, along with its derivatives, will be evaluated as both a standalone solid phase support, and in conjunction with a single molten salt electrolyte. Through surface modification with metal oxide support materials and prototype modeling of scaled-up form factors, the developed solid phase supports will provide the performance and scalability necessary to separate CO₂ from flue gas in the 400-600°C temperature range that is typically found in fossil fuel power plant heat recovery steam generators (HRSG). In Phase I, the team developed high stability support materials with precision manufactured tubular membranes and achieved the highest separation rates recorded for a CO₂ membrane. Phase II efforts will focus on the design of a multi-tube membrane module, long-term stability testing, and materials evaluation, with the goal of commercializing dual phase CO₂ separation membranes as the program progresses into Phase III.